1. Field of the Invention
This invention relates to a comprehensive, uniform, retrofit, commercial and institutional kitchen grease removal and bioremediation system.
2. Description of Prior Art
In as much as grease residue is a by-product of certain forms of cooking, it is naturally understandable that numerous attempts have been made to address the myriad of problems associated with the accumulation of grease in higher volume commercial kitchens:
One area where grease buildup and its removal is most problematic is the exhaust hood, flue, roof surface adjacent to and surrounding the flue, and the kitchen drain lines and grease trap. Grease buildup in these areas is particularly critical in as much as it undermines the sanitary environment of the kitchen, increases the hazard of uncontrollable fires, generates foul odors, promotes insect and rodent infestation and is ultimately the primary cause of sewer stoppage. The generally accepted procedure for dealing with the exhaust hood grease problem is by manual periodic cleaning of the exhaust system when grease accumulations reach unacceptable levels. Grease is removed either manually with scrapers by the kitchen staff or by professional companies using steam and/or power spray washing equipment. In either case, the cleaning is usually done during off hours as it is an incredibly filthy and disruptive process. Handling the waste is a subsequent problem. Invariably, a good portion of the oily effluent ends up in the grease trap via the floor drains. This sudden surge in the volume of grease being discharged into the trap creates additional problems. These will be addressed later. However, the additional volume of greasy sludge shortens the intervals in the pumping (emptying) schedule for the grease trap and increases the frequency of clogged waste lines. The balance of the residue, if properly collected and contained must be disposed of, which, even in the best case scenario remains waste that is hazardous to the environment. An additional problem associated with manual or high pressure cleaning is the increased risk of possible inadvertent contamination of foodstuffs, utensils, and food prep surface areas resulting from failure to contain contaminates being carried in high volumes of water, airborne under pressure.
To avoid the many complications associated with this unpleasant manual procedure, various attempts have been made to devise automatic or self-cleaning hoods, which utilize permanent or removable tortuous air path baffle filters of various designs to catch the grease for removal by water spray. These vent hood systems are expensive and, regardless of their effectiveness, do nothing for the existing facility that cannot justify the complete replacement of a sound, fully functioning, conventional exhaust hood. Other pipe systems utilize fixed or rotating nozzle apparatuses extending along the axis of the exhaust duct (flue) and rely on the impingement of water spray under high pressure to remove grease buildup. Yet other systems are designed with elaborate pipe spray manifolds on wheels that are raised and lowered through the exhaust duct by pulleys and cables and provide coverage to the inside surface of the duct at terrific pressure. The intent is obviously to remove thick encrusted grease and sludge. That these systems utilize a relatively high volume of water in their operation is undeniable. One system in particular uses hot water in the cleaning process. Couple the cost of the water with the energy cost of heating it and it would only seem prudent to activate the system as infrequently as possible. A protracted cleaning schedule allows the daily accumulation of grease to build into the encrusted sludge these systems are obviously designed to address. Furthermore, the infrequent cleaning cycle and high volume of water produces the same waste disposal problems to contend with as the manual method previously discussed.
As with the self-cleaning hoods, it is apparent that these mechanical spray systems would most likely operate at optimum levels when installed in an exhaust duct tailored to be specifically compatible with the washing fixture. Otherwise, the washing fixture would have to be custom designed for each individual duct size and configuration. There seems to be a limitation in their utility in retrofit installations as universality is not apparent.
A search of prior art reveals several power spray washing systems for use inside confined areas such as tanks, pipes and exhaust systems. However, no system is found that provides thorough coverage of solution to adjacent surfaces at pressures less than 20 PSI and volumes as little as one-third gallon per minute. Additionally, no system was discovered that could be installed easily in retrofit and function universally well in a broad array of enclosure configurations having varying dimensions.
Regardless of the effectiveness of the various exhaust system washing devices, they commonly have no impact whatsoever on the grease that collects in and on the inside and outside surfaces of the exhaust fan unit typically mounted at the top of the flue. These grease accumulations generally drain downward from the exhaust fan and pool on the surface of the roof. This condition is undesirable in that, in addition to the obvious fire hazard, it sustains and promotes foul odors and ultimately undermines the integrity of most roofing systems. Hydrocarbons dissolve asphaltic roofing compounds and dramatically shorten roof life. The aspect of preparing or replacing a costly 10-year roofing system in 2 to 5 years is a sobering consideration indeed.
As with the exhaust washing systems, there are most certainly various prior art attempts at a solution to this problem. The exhaust fans have been fitted with collection buckets located below drainage holes drilled in the low point of the fan shroud. The grease that collects in the fan shroud drains through the hole and collects in the bucket below. These buckets require emptying on a regular basis or the grease overflows right back on the roof. Also, this approach does nothing to stop grease from flowing out between the base of the exhaust fan and the top of the flue to join the other grease accumulated on the outside of the fan itself on its downward flow to the roof.
Another prior art solution is to mount a gutter on the outside of the exhaust fan base skirt, which collects a portion of the grease in an integral box mounted on the gutter which is designed to separate grease and rainwater. Like the bucket solution, the collector box must be emptied manually or the grease overflows back onto the roof. Due to broad tolerances being acceptable in building practice, many exhaust flues are built to the exact size of the fan base, or out of square. Either situation leaves little or no free space between exhaust fan base skirts and flue housings for additional flashing components. For this reason, the gutter was designed to mount on the outside of the fan base skirt. Like other collectors, this design does not address the grease that flows outward between the top of the flue and the base of the exhaust fan.
Yet another attempt at addressing the problem has been to build a sand box on the roof surface surrounding the exhaust flue housing to collect the grease prior to its coming into contact with the roof. The ramifications of taking this approach are obvious in that oil and grease are lighter than water, therefore rain floats the grease out on the roof.
A more sophisticated prior art version of the sand box approach comprises an aluminum frame which lays on the roof surface and surrounds the flue housing containing a disposable fiber mesh trap type filter element which is intended to collect and retain the grease to the point of saturation and then be replaced. It would seem that a fiber filter saturated with flammable grease could be considered to have the properties of a wick waiting to be fired. This approach proves to be costly in as much as the filter elements and labor to replace them are not inexpensive.
The effectiveness of all prior art attempts reviewed that deal with the collection of grease is contingent on the timely emptying of the receptacle when full. Other than focusing primarily on keeping grease off the roof to some degree, these systems do little to address the other problems associated with roof top grease including but not limited to fire hazards, rodent and insect infestation, foul odors associated with putrefying grease, and ultimately the final disposition of the grease itself.
Numerous prior art examples have been found that trap and treat grease with enzymes and/or bacterial spores. No doubt, various systems are effective to some extent in reducing the discharged volume of grease deposited in them.
Some prior art deals with the manual introduction of microbes into the sewer drain lines and grease traps of commercial kitchens. More specifically, floor drain covers are repaired to preclude foreign matter from entering the drain lines and microbes are introduced. However, this is a manual process which is obviously done on a periodic schedule. In as much as it is difficult to eliminate the use of cleaners and other chemicals including but not limited to chlorine, which is toxic to microbial life, in the day-to-day operation of a food service facility, the effectiveness of infrequent treatment is easily undermined. The only possible way of assuring enhanced bioremediation is through the daily metered injection of fresh, healthy hydrocarbon-specific microorganisms into the primary floor drain lines and grease trap. No known system exists specifically designed for this purpose.